Motorized advertising displays and illusions are well known in the art from rotated spirally striped barber poles with illusional rising of the stripes, to coaxial elements supported on a swivel and counter-rotated by the torque reaction of a motor between them, and including concealment of the motor in one of the elements. Such elements are rigidly formed, or are of flexible strips which result in unnatural nodular configurations when confined to twist about a vertical axis, or have a uniform diameter throughout their length, or both. None provides the progressive reduction of diameter of a poured stream of liquid as it progressively reduces in its diameter as with the descending stream being accelerated by gravity.
Moreover, where earlier efforts have generally been confined to fixed axes of rotation, lateral movement or gyration of the axis of rotation is desirable to provide animation that depicts mobility and directional flexibility that are recognized suggestively with pouring a beverage successively into several glasses.
It has been noted that when the sides of a twising tape are substantially straight and the tape is comparatively narrow throughout its length even the slightest friction at the swivel may unduly retard the induced bodily rotation of the bottle, the narrower the strip the less rotation and the broader the ribbon the greater the twisting and shortening of the overall length of the ribbon with a corresponding loss of the illusion of the pouring of a liquid. Thus, the illusionary diameter of the stream of liquid beomes greater than the diameter of the neck of the bottle.
Also, it has been noted heretofore that the diameter illusion appears to increase towards the lower end at speeds of rotation low enough to provide the illusion of flowing liquid, and, the imageries induced are vertically spaced enlargements of flow which is more attention getting than realistic for pouring liquids.